首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2655895篇
  免费   187807篇
  国内免费   3700篇
耳鼻咽喉   36184篇
儿科学   86189篇
妇产科学   71001篇
基础医学   397409篇
口腔科学   71489篇
临床医学   239092篇
内科学   511587篇
皮肤病学   58922篇
神经病学   206348篇
特种医学   99464篇
外国民族医学   532篇
外科学   398454篇
综合类   52906篇
现状与发展   12篇
一般理论   921篇
预防医学   206504篇
眼科学   62363篇
药学   198369篇
  11篇
中国医学   5265篇
肿瘤学   144380篇
  2021年   21206篇
  2019年   21632篇
  2018年   30147篇
  2017年   22561篇
  2016年   25356篇
  2015年   28535篇
  2014年   40102篇
  2013年   60234篇
  2012年   83735篇
  2011年   89335篇
  2010年   52848篇
  2009年   49720篇
  2008年   83603篇
  2007年   89366篇
  2006年   89940篇
  2005年   86957篇
  2004年   83380篇
  2003年   80460篇
  2002年   77769篇
  2001年   120275篇
  2000年   123223篇
  1999年   103441篇
  1998年   29941篇
  1997年   26193篇
  1996年   26535篇
  1995年   25035篇
  1994年   23019篇
  1993年   21732篇
  1992年   79666篇
  1991年   78431篇
  1990年   76729篇
  1989年   73994篇
  1988年   68003篇
  1987年   66950篇
  1986年   62520篇
  1985年   60186篇
  1984年   44741篇
  1983年   38034篇
  1982年   22338篇
  1979年   41332篇
  1978年   29615篇
  1977年   24422篇
  1976年   23694篇
  1975年   25946篇
  1974年   30738篇
  1973年   29317篇
  1972年   27470篇
  1971年   26080篇
  1970年   24015篇
  1969年   22953篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
941.
A toxicologic and dermatologic review of cinnamic acid when used as a fragrance ingredient is presented.  相似文献   
942.
Conditions that affect the dentition and the materials utilized to treat these conditions are often unfamiliar to the physician. Dental caries and missing teeth are processes routinely treated in dental practice. Recent improvements in dental materials and techniques permit the dentist to restore the dentition to allow for corrected form, function, esthetics, and patient comfort. This paper describes some of the common conditions that affect the dentition, and the modalities routinely used to treat them.  相似文献   
943.
Malignant fibrous histiocytoma is a neoplasm that can occur both in soft tissue and bone but it is preponderantly found in soft tissue of the extremities. The majority of cases occur in late adult life; and, males are affected more often than females. Most of the patients come to see the doctors because of a mass in various regions and pain. The prognosis is poor, patients usually die from metastasis of the neoplasm to important organ. According to some reports, the neoplasm can occur in oral soft tissue and jaw, thus, dentists should know about important features of the neoplasm in order to be able to diagnose it from other benign oral lesions and can treat correctly.  相似文献   
944.
The aim of the study was to determine, in a group of patients with therapy-resistant burning mouth syndrome (BMS), the possible deficiency of vitamins B1, B2, and B6 and the effect of proper vitamin replacement therapy. Sixteen individuals, aged 47 to 81 years, participated in the study. All underwent a base-line examination comprising anamnestic information, subjective assessment of symptoms, dietary registration, salivary analysis, and serum analysis of thiamine (B1), riboflavine (B2), and pyridoxine (B6). Fifteen individuals had low thiamine and/or riboflavine levels in accordance with suggested levels in the literature and were given replacement therapy. No effect on BMS of vitamin replacement therapy or placebo therapy could be demonstrated.  相似文献   
945.
Neisseria meningitidis group B (MenB) strains isolated from 1976 to 1987 in Finland in 339 patients with invasive infection were sero/subtyped by whole cell enzyme immunoassay using monoclonal antibodies to class 1 and 2/3 outer membrane proteins. 66.7% of the strains could be serotyped (class 2/3) and 70.2% subtyped (class 1). No single phenotype was clearly predominant. The most common serotypes were 4 (18.6%) and 14 (17.4%) and the most common subtypes P1.16 (20.1%) and P1.2 (12.1%). The Norwegian phenotype B:15:P1.16 was seen only rarely (a total of 18 strains). Strains from Northern Finland did not differ from those from Southern Finland: no single phenotype caused the slight increase seen in the incidence of MenB infections in the end of 1970s in the North.  相似文献   
946.
947.
In preventive medicine and occupational health, decision-makers face uncertainty, divergent opinions, and varying needs. In the Swiss aluminum industry, screening for industrial fluorosis illustrates how decision analysis and cost-effectiveness analysis can provide rational and explicit models of decision-making in such contexts. Data on fluoride-exposed potroom workers are used to compare the cost-effectiveness of two strategies: mass screening of fluorosis versus individual detection of the disease on the basis of the worker's symptoms. A decision-analysis and a sensitivity analysis are performed to assess the impact of the screening program for different levels of expected prevalence of the disease. The optimal decision, in economic terms, is the one that minimizes the pension and screening-related costs and maximizes the number of years of full working capacity. Swiss data suggest that a diagnosis of clinical fluorosis is unlikely before 10 years of exposure to fluoride. Between 10 and 30 years of exposure to fluoride, mass screening may be more cost-effective than individual detection of the disease, even when the expected prevalence of the disease in a given industrial setting is less than 10%.  相似文献   
948.
Biopharmaceutic comparison is achieved between commercialized capsules of vinburnine and drops dosage form intended for geriatric pharmacotherapy. Drug bioavailability of vinburnine seems saved, if not significantly increased by the new formulation, in spite of the very important, and well known interindividual variations of vincamine drug products. Only the absorption rate seems statistically increased by drops.  相似文献   
949.
Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 23, No. 5, pp. 540–549, May, 1989.  相似文献   
950.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号